This sounded a lot more like a rant than an etiquette question to be honest. This person seemed to enjoy talking to you, but you're the one who dodged the conversation and lied to avoid seeing her. She did breach some etiquette lines with inappropriate posts on your FB page, but you could simply have corrected that via Private Message.

Defriend and maybe think a bit more about the sort of person you want to be connected to going forward? I don't accept friend requests from people I haven't seen in forever unless I'm actually interested in catching up. If they just want to send a one-time "Hey, how are you" then they can send me a private message without friending me. It's much easier that way.